Managing unscheduled wireless communication in a multiradio device

ABSTRACT

A system for managing the operation of a plurality of radio modules integrated within the same wireless communication device. A control strategy may be employed to manage both more predictable and more spontaneous wireless communication mediums, wherein a local controller may be employed in a radio module utilizing an unscheduled wireless medium, like WLAN, for determining whether adequate time has been allocated to complete a transaction. If the transaction cannot be completed in the allowed time, it may be delayed until adequate time exists, and the delay may be reported so that the time may be reallocated to other radio modules. The radio module may then enter a power-saving mode until the transaction can be completed.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a system for managing multiple radiomodems integrated within a wireless communication device, and morespecifically, to a multiradio control system enabled to create anoperational schedule for a plurality of radio modems, wherein a radiomodem having local control may manage unscheduled communication in viewof various inputs.

2. Description of Prior Art

Modern society has quickly adopted, and become reliant upon, handhelddevices for wireless communication. For example, cellular telephonescontinue to proliferate in the global marketplace due to technologicalimprovements in both the quality of the communication and thefunctionality of the devices. These wireless communication devices(WCDs) have become commonplace for both personal and business use,allowing users to transmit and receive voice, text and graphical datafrom a multitude of geographic locations. The communication networksutilized by these devices span different frequencies and cover differenttransmission distances, each having strengths desirable for variousapplications.

Cellular networks facilitate WCD communication over large geographicareas. These network technologies have commonly been divided bygenerations, starting in the late 1970s to early 1980s with firstgeneration (1G) analog cellular telephones that provided baseline voicecommunication, to modem digital cellular telephones. GSM is an exampleof a widely employed 2G digital cellular network communicating in the900 MHZ/1.8 GHZ bands in Europe and at 850 MHz and 1.9 GHZ in the UnitedStates. This network provides voice communication and also supports thetransmission of textual data via the Short Messaging Service (SMS). SMSallows a WCD to transmit and receive text messages of up to 160characters, while providing data transfer to packet networks, ISDN andPOTS users at 9.6 Kbps. The Multimedia Messaging Service (MMS), anenhanced messaging system allowing for the transmission of sound,graphics and video files in addition to simple text, has also becomeavailable in certain devices. Soon emerging technologies such as DigitalVideo Broadcasting for Handheld Devices (DVB-H) will make streamingdigital video, and other similar content, available via directtransmission to a WCD. While long-range communication networks like GSMare a well-accepted means for transmitting and receiving data, due tocost, traffic and legislative concerns, these networks may not beappropriate for all data applications.

Short-range wireless networks provide communication solutions that avoidsome of the problems seen in large cellular networks. Bluetooth™ is anexample of a short-range wireless technology quickly gaining acceptancein the marketplace. A 1 Mbps Bluetooth™ radio may transmit and receivesdata at a rate of 720 Kbps within a range of 10 meters, and may transmitup to 100 meters with additional power boosting. Enhanced data rate(EDR) technology also available may enable maximum asymmetric data ratesof 1448 Kbps for a 2 Mbps connection and 2178 Kbps for a 3 Mbpsconnection. A user does not actively instigate a Bluetooth™ network.Instead, a plurality of devices within operating range of each other mayautomatically form a network group called a “piconet”. Any device maypromote itself to the master of the piconet, allowing it to control dataexchanges with up to seven “active” slaves and 255 “parked” slaves.Active slaves exchange data based on the clock timing of the master.Parked slaves monitor a beacon signal in order to stay synchronized withthe master. These devices continually switch between various activecommunication and power saving modes in order to transmit data to otherpiconet members. In addition to Bluetooth™ other popular short-rangewireless networks include WLAN (of which “Wi-Fi” local access pointscommunicating in accordance with the IEEE 802.11 standard, is anexample), WUSB, UWB, ZigBee (802.15.4, 802.15.4a), and UHF RFID. All ofthese wireless mediums have features and advantages that make themappropriate for various applications.

More recently, manufacturers have also begun to incorporate variousresources for providing enhanced functionality in WCDs (e.g., componentsand software for performing close-proximity wireless informationexchanges). Sensors and/or scanners may be used to read visual orelectronic information into a device. A transaction may involve a userholding their WCD in proximity to a target, aiming their WCD at anobject (e.g., to take a picture) or sweeping the device over a printedtag or document. Near Field communication (NFC) technologies includemachine-readable mediums such as radio frequency identification (RFID),Infra-red (IR) communication, optical character recognition (OCR) andvarious other types of visual, electronic and magnetic scanning are usedto quickly input desired information into the WCD without the need formanual entry by a user.

Device manufacturers continue to incorporate as many of the previouslydiscussed exemplary communication features as possible into wirelesscommunication devices in an attempt to bring powerful, “do-all” devicesto market. Devices incorporating long-range, short-range and NFCresources often include multiple mediums for each category. This mayallow a WCD to flexibly adjust to its surroundings, for example,communicating both with a WLAN access point and a Bluetooth™communication accessory, possibly at the same time.

Given the large array communication features that may be compiled into asingle device, it is foreseeable that a user will need to employ a WCDto its full potential when replacing other productivity related devices.For example, a user may utilize a fully-functioned WCD to replacetraditional tools such as individual phones, facsimile machines,computers, storage media, etc. which tend to be cumbersome to bothintegrate and transport. In at least one use scenario, a WCD may becommunicating simultaneously over numerous different wireless mediums. Auser may utilize multiple peripheral Bluetooth™ devices (e.g., a headsetand a keyboard) while having a voice conversation over GSM andinteracting with a WLAN access point in order to access the Internet.Problems may occur when these concurrent transactions cause interferencewith each other. Even if a communication medium does not have anidentical operating frequency as another medium, a radio modem may causeextraneous interference to another medium. Further, it is possible forthe combined effects of two or more simultaneously operating radios tocreate intermodulation effects to another bandwidth due to harmoniceffects. These disturbances may cause errors resulting in the requiredretransmission of lost packets, and the overall degradation ofperformance for one or more communication mediums.

Evolving strategies for regulating air time between two or more radiomodems contained in the same device often require a centralized (as asingle component or distributed among various components) communicationcontrol enforcing an operational schedule for all active radio modems,the regulation of which helps to reduce the possibility of communicationcollisions between these active radio modems. However, in order for theoperational schedule to be effective, the interplay of modem activitymust be precisely controlled. This precision may be derived from thecommunication controller being synchronized with the modem by, forexample, knowing the communication backlog and the timing patterns ofthe various active radio modems.

While centrally-controlled wireless resource management may beespecially effective in optimizing some wireless mediums, other wirelessmediums may continue to be problematic. For example, wireless protocolsthat are enabled for carrying synchronous data or may operate in a modethat uses fixed transmission and reception intervals, like GSM andBluetooth™, may be more readily managed by a centralized controllerbecause a schedule may be precisely defined without requiring largebuffer time periods. However, other wireless mediums are not sopredictive, such as WLAN. These unscheduled wireless mediums mustcompete for available transactional windows, and as a result, mayrequire larger time periods to allow for determination of carrieravailability. These determination periods, or contention periods, mayrequire more time to complete a transaction, including both a messageframe to be sent and also an acknowledgement frame to be received. Ifboth of these frames are not sent/received in the time available, themessage is considered unsuccessful, which may waste time in two ways:time is wasted in the initial failed WLAN message attempt (this timecould have been successfully used by another wireless medium), andfurther, time is wasted in attempting to transmit the WLAN messageagain, which may still fail.

What is therefore needed is a system for managing wireless resources inthe same device that utilize conflicting wireless communication mediums.The system should be enabled to manage both more predictable wirelesscommunication mediums and wireless communication mediums that utilizeunscheduled communication in order to avoid communication problems.

SUMMARY OF INVENTION

The present invention includes at least a method, device, computerprogram and radio module for managing the operation of a plurality ofradio modules integrated within the same WCD. In at least one embodimentof the present invention, a control strategy may be employed to manageboth more predictable and more spontaneous wireless mediums. A localcontroller may be employed in a radio module utilizing an unscheduledwireless medium, like WLAN, for determining whether adequate time isallowed for completing a transaction. If the transaction cannot becompleted in the time period, it may be delayed until adequate timeexists.

The local controller, in at least one embodiment of the presentinvention, may consider information provided from various resources inthe WCD before making a determination as to whether there is adequatetime for a transaction. For example, a multiradio controller (MRC) mayprovide schedule information including at least time periods reservedfor a particular communication medium or radio module. The localcontroller may compare the schedule information to informationconcerning messages waiting for transmission while also performingcarrier sensing to determine whether a communication channel isavailable for use. If the MRC allows communication, the channel is free,there is enough time, and any contention periods have expired, thecontroller may initiate a transaction on the communication channel.

If all of the above conditions are not satisfied, the local controllermay perform alternative actions in an attempt to maximize efficiency inthe WCD. For example, the local controller may continue to delay anycommunication transactions until a suitable time period is determined.In conjunction with this delay, the local controller may furtherinitiate optimization procedures such as informing the MRC of availablecommunication bandwidth that may be assigned to another radio module, aswell as placing the delayed radio module in a power saving mode. Theseactions are examples of measures that may be put in place to bothoptimize the usage of available bandwidth while conserving power inaccordance with the present invention.

DESCRIPTION OF DRAWINGS

The invention will be further understood from the following detaileddescription of a preferred embodiment, taken in conjunction withappended drawings, in which:

FIG. 1 discloses an exemplary wireless operational environment,including wireless communication mediums of different effective range.

FIG. 2 discloses a modular description of an exemplary wirelesscommunication device usable with at least one embodiment of the presentinvention.

FIG. 3 discloses an exemplary structural description of the wirelesscommunication device previously described in FIG. 2.

FIG. 4 discloses an exemplary operational description of a wirelesscommunication device utilizing a wireless communication medium inaccordance with at least one embodiment of the present invention.

FIG. 5 discloses an operational example wherein interference occurs whenutilizing multiple radio modems simultaneously within the same wirelesscommunication device.

FIG. 6A discloses an exemplary structural description of a wirelesscommunication device including a multiradio controller in accordancewith at least one embodiment of the present invention.

FIG. 6B discloses a more detailed structural diagram of FIG. 6Aincluding the multiradio controller and the radio modems.

FIG. 6C discloses an exemplary operational description of a wirelesscommunication device including a multiradio controller in accordancewith at least one embodiment of the present invention.

FIG. 7A discloses an exemplary structural description of a wirelesscommunication device including a multiradio control system in accordancewith at least one embodiment of the present invention.

FIG. 7B discloses a more detailed structural diagram of FIG. 7Aincluding the multiradio control system and the radio modems.

FIG. 7C discloses an exemplary operational description of a wirelesscommunication device including a multiradio control system in accordancewith at least one embodiment of the present invention.

FIG. 8A discloses an exemplary structural description of a wirelesscommunication device including a distributed multiradio control systemin accordance with at least one embodiment of the present invention.

FIG. 8B discloses a more detailed structural diagram of FIG. 8Aincluding the distributed multiradio control system and the radiomodems.

FIG. 8C discloses an exemplary operational description of a wirelesscommunication device including a distributed multiradio control systemin accordance with at least one embodiment of the present invention.

FIG. 9A discloses an exemplary structural description of a wirelesscommunication device including a distributed multiradio control systemin accordance with an alternative embodiment of the present invention.

FIG. 9B discloses a more detailed structural diagram of FIG. 9Aincluding the distributed multiradio control system and the radiomodems.

FIG. 9C discloses an exemplary operational description of a wirelesscommunication device including a distributed multiradio control systemin accordance with the alternative embodiment of the present inventiondisclosed in FIG. 9A.

FIG. 10 discloses an exemplary information packet usable with at leastone embodiment of the present invention.

FIG. 11A discloses an example of a local controller incorporated into aradio modem in accordance with at least one embodiment of the presentinvention.

FIG. 11B discloses an exemplary functional diagram of a radio modemincluding a local controller in accordance with at least one embodimentof the present invention.

FIG. 12A discloses an example of an unscheduled wireless communicationmedium transmission experiencing problems in accordance with at leastone embodiment of the present invention.

FIG. 12B discloses an example of an unscheduled wireless communicationmedium transmission management in accordance with at least oneembodiment of the present invention.

FIG. 13A discloses a back-off timing control diagram for an examplecommunication scenario in accordance with at least one embodiment of thepresent invention.

FIG. 13B discloses a back-off timing control diagram for another examplecommunication scenario in accordance with at least one embodiment of thepresent invention.

FIG. 14 discloses an exemplary flowchart for managing an unscheduledwireless communication medium in accordance with at least one embodimentof the present invention.

FIG. 15 discloses an exemplary flowchart for implementing a back-offtimer with respect to schedule and carrier condition in accordance withat least one embodiment of the present invention.

FIG. 16 discloses an exemplary flowchart for implementing a back-offtimer with respect to transmit and receive permission in accordance withat least one embodiment of the present invention.

DESCRIPTION OF PREFERRED EMBODIMENT

While the invention has been described in preferred embodiments, variouschanges can be made therein without departing from the spirit and scopeof the invention, as described in the appended claims.

I. Wireless Communication Over Different Communication Networks

A WCD may both transmit and receive information over a wide array ofwireless communication networks, each with different advantagesregarding speed, range, quality (error correction), security (encoding),etc. These characteristics will dictate the amount of information thatmay be transferred to a receiving device, and the duration of theinformation transfer. FIG. 1 includes a diagram of a WCD and how itinteracts with various types of wireless networks.

In the example pictured in FIG. 1, user 110 possesses WCD 100. Thisdevice may be anything from a basic cellular handset to a more complexdevice such as a wirelessly enabled palmtop or laptop computer. NearField Communication (NFC) 130 includes various transponder-typeinteractions wherein normally only the scanning device requires its ownpower source. WCD 100 scans source 120 via short-range communication. Atransponder in source 120 may use the energy and/or clock signalcontained within the scanning signal, as in the case of RFIDcommunication, to respond with data stored in the transponder. Thesetypes of technologies usually have an effective transmission range onthe order of ten feet, and may be able to deliver stored data in amountsfrom a bit to over a megabit (or 125 Kbytes) relatively quickly. Thesefeatures make such technologies well suited for identification purposes,such as to receive an account number for a public transportationprovider, a key code for an automatic electronic door lock, an accountnumber for a credit or debit transaction, etc.

The transmission range between two devices may be extended if bothdevices are capable of performing powered communication. Short-rangeactive communication 140 includes applications wherein the sending andreceiving devices are both active. An exemplary situation would includeuser 110 coming within effective transmission range of a Bluetooth™,WLAN, UWB, WUSB, etc. access point. In the case of Bluetooth™, a networkmay automatically be established to transmit information to WCD 100possessed by user 110. This data may include information of aninformative, educational or entertaining nature. The amount ofinformation to be conveyed is unlimited, except that it must all betransferred in the time when user 110 is within effective transmissionrange of the access point. Due to the higher complexity of thesewireless networks, additional time is also required to establish theinitial connection to WCD 100, which may be increased if many devicesare queued for service in the area proximate to the access point. Theeffective transmission range of these networks depends on thetechnology, and may be from some 30 ft. to over 300 ft. with additionalpower boosting.

Long-range networks 150 are used to provide virtually uninterruptedcommunication coverage for WCD 100. Land-based radio stations orsatellites are used to relay various communication transactionsworldwide. While these systems are extremely functional, the use ofthese systems is often charged on a per-minute basis to user 110, notincluding additional charges for data transfer (e.g., wireless Internetaccess). Further, the regulations covering these systems may causeadditional overhead for both the users and providers, making the use ofthese systems more cumbersome.

II. Wireless Communication Device

As previously described, the present invention may be implemented usinga variety of wireless communication equipment. Therefore, it isimportant to understand the communication tools available to user 110before exploring the present invention. For example, in the case of acellular telephone or other handheld wireless devices, the integrateddata handling capabilities of the device play an important role infacilitating transactions between the transmitting and receivingdevices.

FIG. 2 discloses an exemplary modular layout for a wirelesscommunication device usable with the present invention. WCD 100 isbroken down into modules representing the functional aspects of thedevice. These functions may be performed by the various combinations ofsoftware and/or hardware components discussed below.

Control module 210 regulates the operation of the device. Inputs may bereceived from various other modules included within WCD 100. Forexample, interference sensing module 220 may use various techniquesknown in the art to sense sources of environmental interference withinthe effective transmission range of the wireless communication device.Control module 210 interprets these data inputs, and in response, mayissue control commands to the other modules in WCD 100.

Communications module 230 incorporates all of the communication aspectsof WCD 100. As shown in FIG. 2, communications module 230 may include,for example, long-range communications module 232, short-rangecommunications module 234 and NFC module 236. Communications module 230may utilize one or more of these sub-modules to receive a multitude ofdifferent types of communication from both local and long distancesources, and to transmit data to recipient devices within thetransmission range of WCD 100. Communications module 230 may betriggered by control module 210, or by control resources local to themodule responding to sensed messages, environmental influences and/orother devices in proximity to WCD 100.

User interface module 240 includes visual, audible and tactile elementswhich allow the user 110 to receive data from, and enter data into, thedevice. The data entered by user 110 may be interpreted by controlmodule 210 to affect the behavior of WCD 100. User-inputted data mayalso be transmitted by communications module 230 to other devices withineffective transmission range. Other devices in transmission range mayalso send information to WCD 100 via communications module 230, andcontrol module 210 may cause this information to be transferred to userinterface module 240 for presentment to the user.

Applications module 250 incorporates all other hardware and/or softwareapplications on WCD 100. These applications may include sensors,interfaces, utilities, interpreters, data applications, etc., and may beinvoked by control module 210 to read information provided by thevarious modules and in turn supply information to requesting modules inWCD 100.

FIG. 3 discloses an exemplary structural layout of WCD 100 according toan embodiment of the present invention that may be used to implement thefunctionality of the modular system previously described in FIG. 2.Processor 300 controls overall device operation. As shown in FIG. 3,processor 300 is coupled to one or more communications sections 310, 320and 340. Processor 300 may be implemented with one or moremicroprocessors that are each capable of executing software instructionsstored in memory 330.

Memory 330 may include random access memory (RAM), read only memory(ROM), and/or flash memory, and stores information in the form of dataand software components (also referred to herein as modules). The datastored by memory 330 may be associated with particular softwarecomponents. In addition, this data may be associated with databases,such as a bookmark database or a business database for scheduling,email, etc.

The software components stored by memory 330 include instructions thatcan be executed by processor 300. Various types of software componentsmay be stored in memory 330. For instance, memory 330 may store softwarecomponents that control the operation of communication sections 310, 320and 340. Memory 330 may also store software components including afirewall, a service guide manager, a bookmark database, user interfacemanager, and any communication utilities modules required to support WCD100.

Long-range communications 310 performs functions related to the exchangeof information over large geographic areas (such as cellular networks)via an antenna. These communication methods include technologies fromthe previously described 1G to 3G. In addition to basic voicecommunication (e.g., via GSM), long-range communications 310 may operateto establish data communication sessions, such as General Packet RadioService (GPRS) sessions and/or Universal Mobile TelecommunicationsSystem (UMTS) sessions. Also, long-range communications 310 may operateto transmit and receive messages, such as short messaging service (SMS)messages and/or multimedia messaging service (MMS) messages.

As a subset of long-range communications 310, or alternatively operatingas an independent module separately connected to processor 300,transmission receiver 312 allows WCD 100 to receive transmissionmessages via mediums such as Digital Video Broadcast for HandheldDevices (DVB-H). These transmissions may be encoded so that only certaindesignated receiving devices may access the transmission content, andmay contain text, audio or video information. In at least one example,WCD 100 may receive these transmissions and use information containedwithin the transmission signal to determine if the device is permittedto view the received content.

Short-range communications 320 is responsible for functions involvingthe exchange of information across short-range wireless networks. Asdescribed above and depicted in FIG. 3, examples of such short-rangecommunications 320 are not limited to Bluetooth™, WLAN, UWB and WirelessUSB connections. Accordingly, short-range communications 320 performsfunctions related to the establishment of short-range connections, aswell as processing related to the transmission and reception ofinformation via such connections.

NFC 340, also depicted in FIG. 3, may provide functionality related tothe short-range scanning of machine-readable data. For example,processor 300 may control components in NFC 340 to generate RF signalsfor activating an RFID transponder, and may in turn control thereception of signals from an RFID transponder. Other short-rangescanning methods for reading machine-readable data that may be supportedby the NFC 340 are not limited to IR communication, linear and 2-D(e.g., QR) bar code readers (including processes related to interpretingUPC labels), and optical character recognition devices for readingmagnetic, UV, conductive or other types of coded data that may beprovided in a tag using suitable ink. In order for the NFC 340 to scanthe aforementioned types of machine-readable data, the input device mayinclude optical detectors, magnetic detectors, CCDs or other sensorsknown in the art for interpreting machine-readable information.

As further shown in FIG. 3, user interface 350 is also coupled toprocessor 300. User interface 350 facilitates the exchange ofinformation with a user. FIG. 3 shows that user interface 350 includes auser input 360 and a user output 370. User input 360 may include one ormore components that allow a user to input information. Examples of suchcomponents include keypads, touch screens, and microphones. User output370 allows a user to receive information from the device. Thus, useroutput portion 370 may include various components, such as a display,light emitting diodes (LED), tactile emitters and one or more audiospeakers. Exemplary displays include liquid crystal displays (LCDs), andother video displays.

WCD 100 may also include one or more transponders 380. This isessentially a passive device that may be programmed by processor 300with information to be delivered in response to a scan from an outsidesource. For example, an RFID scanner mounted in an entryway maycontinuously emit radio frequency waves. When a person with a devicecontaining transponder 380 walks through the door, the transponder isenergized and may respond with information identifying the device, theperson, etc. In addition, a scanner may be mounted (e.g., as previouslydiscussed above with regard to examples of NFC 340) in WCD 100 so thatit can read information from other transponders in the vicinity.

Hardware corresponding to communications sections 310, 312, 320 and 340provide for the transmission and reception of signals. Accordingly,these portions may include components (e.g., electronics) that performfunctions, such as modulation, demodulation, amplification, andfiltering. These portions may be locally controlled, or controlled byprocessor 300 in accordance with software communication componentsstored in memory 330.

The elements shown in FIG. 3 may be constituted and coupled according tovarious techniques in order to produce the functionality described inFIG. 2. One such technique involves coupling separate hardwarecomponents corresponding to processor 300, communications sections 310,312 and 320, memory 330, NFC 340, user interface 350, transponder 380,etc. through one or more bus interfaces (which may be wired or wirelessbus interfaces). Alternatively, any and/or all of the individualcomponents may be replaced by an integrated circuit in the form of aprogrammable logic device, gate array, ASIC, multi-chip module, etc.programmed to replicate the functions of the stand-alone devices. Inaddition, each of these components is coupled to a power source, such asa removable and/or rechargeable battery (not shown).

The user interface 350 may interact with a communication utilitiessoftware component, also contained in memory 330, which provides for theestablishment of service sessions using long-range communications 310and/or short-range communications 320. The communication utilitiescomponent may include various routines that allow the reception ofservices from remote devices according to mediums such as the WirelessApplication Medium (WAP), Hypertext Markup Language (HTML) variants likeCompact HTML (CHTML), etc.

III. Exemplary Operation of a Wireless Communication Device IncludingPotential Interference Problems Encountered.

FIG. 4 discloses a stack approach to understanding the operation of aWCD in accordance with at least one embodiment of the present invention.At the top level 400, user 110 interacts with WCD 100. The interactioninvolves user 110 entering information via user input 360 and receivinginformation from user output 370 in order to activate functionality inapplication level 410. In the application level, programs related tospecific functionality within the device interact with both the user andthe system level. These programs include applications for visualinformation (e.g., web browser, DVB-H receiver, etc.), audio information(e.g., cellular telephone, voice mail, conferencing software, DAB oranalog radio receiver, etc.), recording information (e.g., digitalphotography software, word processing, scheduling, etc.) or otherinformation processing. Actions initiated at application level 410 mayrequire information to be sent from or received into WCD 100. In theexample of FIG. 4, data is requested to be sent to a recipient devicevia Bluetooth™ communication. As a result, application level 410 maythen call resources in the system level to initiate the requiredprocessing and routing of data.

System level 420 processes data requests and routes the data fortransmission. Processing may include, for example, calculation,translation, conversion and/or packetizing the data. The information maythen be routed to an appropriate communication resource in the servicelevel. If the desired communication resource is active and available inthe service level 430, the packets may be routed to a radio modem fordelivery via wireless transmission. There may be a plurality of modemsoperating using different wireless mediums. For example, in FIG. 4,modem 4 is activated and able to send packets using Bluetooth™communication. However, a radio modem (as a hardware resource) need notbe dedicated only to a specific wireless medium, and may be used fordifferent types of communication depending on the requirements of thewireless medium and the hardware characteristics of the radio modem.

FIG. 5 discloses a situation wherein the above described exemplaryoperational process may cause more than one radio modem to becomeactive. In this case, WCD 100 is both transmitting and receivinginformation via wireless communication over a multitude of mediums. WCD100 may be interacting with various secondary devices such as thosegrouped at 500. For example, these devices may include cellular handsetscommunicating via long-range wireless communication like GSM, wirelessheadsets communicating via Bluetooth™, Internet access pointscommunicating via WLAN, etc.

Problems may occur when some or all of these communications are carriedon simultaneously. As further shown in FIG. 5, multiple modems operatingsimultaneously may cause interference for each other. Such a situationmay be encountered when WCD 100 is communicating with more than oneexternal device (as previously described). In an exemplary extreme case,devices with modems simultaneously communicating via Bluetooth™, WLANand wireless USB would encounter substantial overlap since all of thesewireless mediums operate in the 2.4 GHz band. The interference, shown asan overlapping portion of the fields depicted in FIG. 5, would causepackets to be lost and the need for retransmission of these lostpackets. Retransmission requires that future time slots be used toretransmit lost information, and therefore, overall communicationperformance will at least be reduced, if the signal is not lostcompletely. The present invention, in at least one embodiment, seeks tomanage problematic situations where possibly conflicting communicationsmay be occurring simultaneously so that interference is minimized ortotally avoided, and as a result, speed and quality are maximized.

IV. A Wireless Communication Device Including a Multiradio Controller.

In an attempt to better manage communication in WCD 100, an additionalcontroller dedicated to managing wireless communication may beintroduced. WCD 100, as pictured in FIG. 6A, includes a multiradiocontroller (MRC) 600 in accordance with at least one embodiment of thepresent invention. MRC 600 is coupled to the master control system ofWCD 100. This coupling enables MRC 600 to communicate with radio modemsor other similar devices in communications modules 310 312, 320 and 340via the master operating system of WCD 100.

FIG. 6B discloses in detail at least one embodiment of WCD 100, whichmay include multiradio controller (MRC) 600 introduced in FIG. 6A inaccordance with at least one embodiment of the present invention. MRC600 includes common interface 620 by which information may be sent orreceived through master control system 640. Radio modems 610 and otherdevices 630 may also be referred to as “modules” in this disclosure asthey may contain supporting hardware and/or software resources inaddition to the modem itself. These resources may include control,interface and/or processing resources. For example, each radio modem 610or similar communication device 630 (e.g., an RFID scanner for scanningmachine-readable information) may also include some sort of commoninterface 620 for communicating with master control system 640. As aresult, all information, commands, etc. occurring between radio modems610, similar devices 630 and MRC 600 are conveyed by the communicationresources of master control system 640. The possible effect of sharingcommunication resources with all the other functional modules within WCD100 will be discussed with respect to FIG. 6C.

FIG. 6C discloses an operational diagram similar to FIG. 4 including theeffect of MRC 600 in accordance with at least one embodiment of thepresent invention. In this system MRC 600 may receive operational datafrom the master operating system of WCD 100, concerning for exampleapplications running in application level 410, and status data from thevarious radio communication devices in service level 430. MRC 600 mayuse this information to issue scheduling commands to the communicationdevices in service level 430 in an attempt to avoid communicationproblems. However, problems may occur when the operations of WCD 100 arefully employed. Since the various applications in application level 410,the operating system in system level 420, the communication devices inservice level 430 and MRC 600 must all share the same communicationsystem, delays may occur when all aspects of WCD 100 are trying tocommunicate on the common interface system 620. As a result, delaysensitive information regarding both communication resource statusinformation and radio modem 610 control information may become delayed,nullifying any beneficial effect from MRC 600. Therefore, a systembetter able to handle the differentiation and routing of delay sensitiveinformation is required if the beneficial effect of MRC 600 is to berealized.

V. A Wireless Communication Device Including a Multiradio ControlSystem.

FIG. 7A introduces MRC 600 as part of a multiradio control system (MCS)700 in WCD 100 in accordance with at least one embodiment of the presentinvention. MCS 700 directly links the communication resources of modules310, 312, 320 and 340 to MRC 600. MCS 700 may provide a dedicatedlow-traffic communication structure for carrying delay sensitiveinformation both to and from MRC 600.

Additional detail is shown in FIG. 7B. MCS 700 forms a direct linkbetween MRC 600 and the communication resources of WCD 100. This linkmay be established by a system of dedicated MCS interfaces 710 and 760.For example, MCS interface 760 may be coupled to MRC 600. MCS Interfaces710 may connect radio modems 610 and other similar communication devices630 to MCS 700 in order to form an information conveyance for allowingdelay sensitive information to travel to and from MRC 600. In this way,the abilities of MRC 600 are no longer influenced by the processing loadof master control system 640. As a result, any information stillcommunicated by master control system 640 to and from MRC 600 may bedeemed delay tolerant, and therefore, the actual arrival time of thisinformation does not substantially influence system performance. On theother hand, all delay sensitive information is directed to MCS 700, andtherefore is insulated from the loading of the master control system.

The effect of MCS 700 is seen in FIG. 7C in accordance with at least oneembodiment of the present invention. Information may now be received inMRC 600 from at least two sources. System level 420 may continue toprovide information to MRC 600 through master control system 640. Inaddition, service level 430 may specifically provide delay sensitiveinformation conveyed by MCS 700. MRC 600 may distinguish between thesetwo classes of information and act accordingly. Delay tolerantinformation may include information that typically does not change whena radio modem is actively engaged in communication, such as radio modeinformation (e.g., GPRS, Bluetooth™, WLAN, etc.), priority informationthat may be defined by user settings, the specific service the radio isdriving (QoS, real time/non real time), etc. Since delay tolerantinformation changes infrequently, it may be delivered in due course bymaster control system 640 of WCD 100. Alternatively, delay sensitive (ortime sensitive) information includes at least modem operationalinformation that frequently changes during the course of a wirelessconnection, and therefore, requires immediate update. As a result, delaysensitive information may need to be delivered directly from theplurality of radio modems 610 through the MCS interfaces 710 and 760 toMRC 600, and may include radio modem synchronization information. Delaysensitive information may be provided in response to a request by MRC600, or may be delivered as a result of a change in radio modem settingsduring transmission, as will be discussed with respect tosynchronization below.

VI. A Wireless Communication Device Including a Distributed MultiradioControl System.

FIG. 8A discloses an alternative configuration in accordance with atleast one embodiment of the present invention, wherein a distributedmultiradio control system (MCS) 700 is introduced into WCD 100.Distributed MCS 700 may, in some cases, be deemed to provide anadvantage over a centralized MRC 600 by distributing these controlfeatures into already necessary components within WCD 100. As a result,a substantial amount of the communication management operations may belocalized to the various communication resources, such as radio modems(modules) 610, reducing the overall amount of control command traffic inWCD 100.

MCS 700, in this example, may be implemented utilizing a variety of busstructures, including the I²C interface commonly found in portableelectronic devices, as well as emerging standards such as SLIMbus thatare now under development. I²C is a multi-master bus, wherein multipledevices can be connected to the same bus and each one can act as amaster through initiating a data transfer. An I²C bus contains at leasttwo communication lines, an information line and a clock line. When adevice has information to transmit, it assumes a master role andtransmits both its clock signal and information to a recipient device.SLIMbus, on the other hand, utilizes a separate, non-differentialphysical layer that runs at rates of 50 Mbits/s or slower over just onelane. It is being developed by the Mobile Industry Processor Interface(MIPI) Alliance to replace today's I²C and I²S interfaces while offeringmore features and requiring the same or less power than the twocombined.

MCS 700 directly links distributed control components 702 in modules310, 312, 320 and 340. Another distributed control component 704 mayreside in master control system 640 of WCD 100. It is important to notethat distributed control component 704 shown in processor 300 is notlimited only to this embodiment, and may reside in any appropriatesystem module within WCD 100. The addition of MCS 700 provides adedicated low-traffic communication structure for carrying delaysensitive information both to and from the various distributed controlcomponents 702.

The exemplary embodiment disclosed in FIG. 8A is described with moredetail in FIG. 8B. MCS 700 forms a direct link between distributedcontrol components 702 within WCD 100. Distributed control components702 in radio modems 610 (together forming a “module”) may, for example,consist of MCS interface 710, radio activity controller 720 andsynchronizer 730. Radio activity controller 720 uses MCS interface 710to communicate with distributed control components in other radio modems610. Synchronizer 730 may be utilized to obtain timing information fromradio modem 610 to satisfy synchronization requests from any of thedistributed control components 702. Radio activity controller 702 mayalso obtain information from master control system 640 (e.g., fromdistributed control component 704) through common interface 620. As aresult, any information communicated by master control system 640 toradio activity controller 720 through common interface 620 may be deemeddelay tolerant, and therefore, the actual arrival time of thisinformation does not substantially influence communication systemperformance. On the other hand, all delay sensitive information may beconveyed by MCS 700, and therefore is insulated from master controlsystem overloading.

As previously stated, a distributed control component 704 may existwithin master control system 640. Some aspects of this component mayreside in processor 300 as, for example, a running software routine thatmonitors and coordinates the behavior of radio activity controllers 720.Processor 300 is shown to contain priority controller 740. Prioritycontroller 740 may be utilized to monitor active radio modems 610 inorder to determine priority amongst these devices. Priority may bedetermined by rules and/or conditions stored in priority controller 740.Modems that become active may request priority information from prioritycontroller 740. Further, modems that go inactive may notify prioritycontroller 740 so that the relative priority of the remaining activeradio modems 610 may be adjusted accordingly. Priority information isusually not considered delay sensitive because it is mainly updated whenradio modems 610 activate/deactivate, and therefore, does not frequentlychange during the course of an active communication connection in radiomodems 610. As a result, this information may be conveyed to radiomodems 610 using common interface system 620 in at least one embodimentof the present invention.

At least one effect of a distributed control MCS 700 is seen in FIG. 8C.System level 420 may continue to provide delay tolerant information todistributed control components 702 through master control system 640. Inaddition, distributed control components 702 in service level 430, suchas modem activity controllers 720, may exchange delay sensitiveinformation with each other via MCS 700. Each distributed controlcomponent 702 may distinguish between these two classes of informationand act accordingly. Delay tolerant information may include informationthat typically does not change when a radio modem is actively engaged incommunication, such as radio mode information (e.g., GPRS, Bluetooth™,WLAN, etc.), priority information that may be defined by user settings,the specific service the radio is driving (QoS, real time/non realtime), etc. Since delay tolerant information changes infrequently, itmay be delivered in due course by master control system 640 of WCD 100.Alternatively, delay sensitive (or time sensitive) information mayinclude at least modem operational information that frequently changesduring the course of a wireless connection, and therefore, requiresimmediate update. Delay sensitive information needs to be delivereddirectly between distributed control components 702, and may includeradio modem synchronization and activity control information. Delaysensitive information may be provided in response to a request, or maybe delivered as a result of a change in radio modem, which will bediscussed with respect to synchronization below.

MCS interface 710 may be used to (1) Exchange synchronizationinformation, and (2) Transmit identification or prioritizationinformation between various radio activity controllers 720. In addition,as previously stated, MCS interface 710 is used to communicate the radioparameters that are delay sensitive from a controlling point of view.MCS interface 710 can be shared between different radio modems(multipoint) but it cannot be shared with any other functionality thatcould limit the usage of MCS interface 710 from a latency point of view.

The control signals sent on MCS 700 that may enable/disable a radiomodem 610 should be built on a modem's periodic events. Each radioactivity controller 720 may obtain this information about a radiomodem's periodic events from synchronizer 730. This kind of event canbe, for example, frame clock event in GSM (4.615 ms), slot clock eventin Bluetooth™ (625 us) or targeted beacon transmission time in WLAN (100ms) or any multiple of these. A radio modem 610 may send itssynchronization indications when (1) Any radio activity controller 720requests it, (2) a radio modem internal time reference is changed (e.g.due to handover or handoff). The latency requirement for thesynchronization signal is not critical as long as the delay is constantwithin a few microseconds. The fixed delays can be taken into account inthe scheduling logic of radio activity controller 710.

For predictive wireless communication mediums, the radio modem activitycontrol may be based on the knowledge of when the active radio modems610 are about to transmit (or receive) in the specific connection modein which the radios are currently operating. The connection mode of eachradio modem 610 may be mapped to the time domain operation in theirrespective radio activity controller 720. As an example, for a GSMspeech connection, priority controller 740 may have knowledge about alltraffic patterns of GSM. This information may be transferred to theappropriate radio activity controller 720 when radio modem 610 becomesactive, which may then recognize that the speech connection in GSMincludes one transmission slot of length 577 μs, followed by an emptyslot after which is the reception slot of 577 μs, two empty slots,monitoring (RX on), two empty slots, and then it repeats. Dual transfermode means two transmission slots, empty slot, reception slot, emptyslot, monitoring and two empty slots. When all traffic patterns that areknown a priori by the radio activity controller 720, it only needs toknow when the transmission slot occurs in time to gain knowledge of whenthe GSM radio modem is active. This information may be obtained bysynchronizer 730. When the active radio modem 610 is about to transmit(or receive) it must check every time whether the modem activity controlsignal from its respective radio activity controller 720 permits thecommunication. Radio activity controller 720 is always either allowingor disabling the transmission of one full radio transmission block (e.g.GSM slot).

VII. A Wireless Communication Device Including an Alternative Example ofa Distributed Multiradio Control System.

An alternative distributed control configuration in accordance with atleast one embodiment of the present invention is disclosed in FIG.9A-9C. In FIG. 9A, distributed control components 702 continue to belinked by MCS 700. However, now distributed control component 704 isalso directly coupled to distributed control components 702 via an MCSinterface. As a result, distributed control component 704 may alsoutilize and benefit from MCS 700 for transactions involving the variouscommunication components of WCD 100.

Referring now to FIG. 9B, the inclusion of distributed control component704 onto MCS 700 is shown in more detail. Distributed control component704 includes at least priority controller 740 coupled to MCS interface750. MCS interface 750 allows priority controller 740 to sendinformation to, and receive information from, radio activity controllers720 via a low-traffic connection dedicated to the coordination ofcommunication resources in WCD 100. As previously stated, theinformation provided by priority controller 740 may not be deemed delaysensitive information, however, the provision of priority information toradio activity controllers 720 via MCS 700 may improve the overallcommunication efficiency of WCD 100. Performance may improve becausequicker communication between distributed control components 702 and 704may result in faster relative priority resolution in radio activitycontrollers 720. Further, the common interface system 620 of WCD 100will be relieved of having to accommodate communication traffic fromdistributed control component 704, reducing the overall communicationload in master control system 640. Another benefit may be realized incommunication control flexibility in WCD 100. New features may beintroduced into priority controller 740 without worrying about whetherthe messaging between control components will be delay tolerant orsensitive because an MCS interface 710 is already available at thislocation.

FIG. 9C discloses the operational effect of the enhancements seen in thecurrent alternative embodiment of the present invention on communicationin WCD 100. The addition of an alternative route for radio modem controlinformation to flow between distributed control components 702 and 704may both improve the communication management of radio activitycontrollers 720 and lessen the burden on master control system 640. Inthis embodiment, all distributed control components of MCS 700 arelinked by a dedicated control interface, which provides immunity tocommunication coordination control messaging in WCD 100 when the mastercontrol system 640 is experiencing elevated transactional demands.

An example message packet 900 is disclosed in FIG. 10 in accordance withat least one embodiment of the present invention. Example message packet900 includes activity pattern information that may be formulated by MRC600 or radio activity controller 720. The data payload of packet 900 mayinclude, in at least one embodiment of the present invention, at leastMessage ID information, allowed/disallowed transmission (Tx) periodinformation, allowed/disallowed reception (Rx) period information, Tx/Rxperiodicity (how often the Tx/Rx activities contained in the periodinformation occur), and validity information describing when theactivity pattern becomes valid and whether the new activity pattern isreplacing or added to the existing one. The data payload of packet 900,as shown, may consist of multiple allowed/disallowed periods fortransmission or reception (e.g., Tx period 1, 2 . . . ) each containingat least a period start time and a period end time during which radiomodem 610 may either be permitted or prevented from executing acommunication activity. While the distributed example of MCS 700 mayallow radio modem control activity to be controlled real-time (e.g.,more control messages with finer granularity), the ability to includemultiple allowed/disallowed periods into a single message packet 900 maysupport radio activity controllers 720 in scheduling radio modembehavior for longer periods of time, which may result in a reduction inmessage traffic. Further, changes in radio modem 610 activity patternsmay be amended using the validity information in each message packet900.

The modem activity control signal (e.g., packet 900) may be formulatedby MRC 600 or radio activity controller 720 and transmitted on MCS 700.The signal includes activity periods for Tx and Rx separately, and theperiodicity of the activity for the radio modem 610. While the nativeradio modem clock is the controlling time domain (never overwritten),the time reference utilized in synchronizing the activity periods tocurrent radio modem operation may be based on one of at least twostandards. In a first example, a transmission period may start after apre-defined amount of synchronization events have occurred in radiomodem 610. Alternatively, all timing for MRC 600 or between distributedcontrol components 702 may be standardized around the system clock forWCD 100. Advantages and disadvantages exist for both solutions. Using adefined number of modem synchronization events is beneficial becausethen all timing is closely aligned with the radio modem clock. However,this strategy may be more complicated to implement than basing timing onthe system clock. On the other hand, while timing based on the systemclock may be easier to implement as a standard, conversion to modemclock timing must necessarily be implemented whenever a new activitypattern is installed in radio modem 610.

The activity period may be indicated as start and stop times. If thereis only one active connection, or if there is no need to schedule theactive connections, the modem activity control signal may be set alwayson allowing the radio modems to operate without restriction. The radiomodem 610 should check whether the transmission or reception is allowedbefore attempting actual communication. The activity end time can beused to check the synchronization. Once the radio modem 610 has endedthe transaction (slot/packet/burst), it can check whether the activitysignal is still set (it should be due to margins). If this is not thecase, the radio modem 610 can initiate a new synchronization with MRC600 or with radio activity controller 720 through synchronizer 730. Thesame happens if a radio modem time reference or connection mode changes.A problem may occur if radio activity controller 720 runs out of themodem synchronization and starts to apply modem transmission/receptionrestrictions at the wrong time. Due to this, modem synchronizationsignals need to be updated periodically. The more active wirelessconnections, the more accuracy is required in synchronizationinformation.

VIII. Radio Modem Interface to Other Devices.

As a part of information acquisition services, the MCS interface 710needs to send information to MRC 600 (or radio activity controllers 720)about periodic events of the radio modems 610. Using its MCS interface710, the radio modem 610 may indicate a time instance of a periodicevent related to its operation. In practice these instances are timeswhen radio modem 610 is active and may be preparing to communicate orcommunicating. Events occurring prior to or during a transmission orreception mode may be used as a time reference (e.g., in case of GSM,the frame edge may be indicated in a modem that is not necessarilytransmitting or receiving at that moment, but we know based on the frameclock that the modem is going to transmit [x]ms after the frame clockedge). Basic principle for such timing indications is that the event isperiodic in nature. Every incident needs not to be indicated, but theMRC 600 may calculate intermediate incidents itself. In order for thatto be possible, the controller would also require other relevantinformation about the event, e.g. periodicity and duration. Thisinformation may be either embedded in the indication or the controllermay get it by other means. Most importantly, these timing indicationsneed to be such that the controller can acquire a radio modem's basicperiodicity and timing. The timing of an event may either be in theindication itself, or it may be implicitly defined from the indicationinformation by MRC 600 (or radio activity controller 720).

In general terms these timing indications need to be provided onperiodic events like: schedule broadcasts from a base station (typicallyTDMA/MAC frame boundaries) and own periodic transmission or receptionperiods (typically Tx/Rx slots). Those notifications need to be issuedby the radio modem 610: (1) on network entry (i.e. modem acquiresnetwork synchrony), (2) on periodic event timing change e.g. due to ahandoff or handover and (3) as per the policy and configuration settingsin the multiradio controller (monolithic or distributed).

In at least one embodiment of the present invention, the variousmessages exchanged between the aforementioned communication componentsin WCD 100 may be used to dictate behavior on both a local (radio modemlevel) and global (WCD level) basis. MRC 600 or radio activitycontroller 720 may deliver a schedule to radio modem 610 with the intentof controlling that specific modem, however, radio modem 610 may not becompelled to conform to this schedule. The basic principle is that radiomodem 610 is not only operating according to multiradio controlinformation (e.g., operates only when MRC 600 allows) but is alsoperforming internal scheduling and link adaptation while taking MRCscheduling information into account.IX. Management of Unscheduled Wireless Communication Mediums in RadioModules.

FIG. 11A discloses a system for controlling an unscheduled wirelessmedium, such as WLAN, in a radio modem or module 610 in accordance withat least one embodiment of the present invention. While WLAN has beenused for the sake of explanation in the following disclosure, thepresent invention is not limited only to WLAN, but may instead byemployed to manage any wireless communication medium that may act in anunscheduled manner. This embodiment is distinct from the distributedsolution previously discussed in this disclosure, which is clearly shownin FIG. 11A. Example 1100 includes a local controller 1102 integratedwithin the centrally controlled configuration of the present invention.In this scenario, MRC 600 may still retain primary control over theoperations of all modems in WCD 100, however, local controller 1102 mayact to control the activity of the particular radio modem 610 to whichit is coupled within the parameters defined by MRC 600. While localcontroller 1102 is shown as a component of the module making up radiomodem 610, this controller may also be a separate component coupled toradio modem 610 via common interface 620 or MCS interface 710.

Example 1110 shows another example wherein a local controller beingintegrated into a distributed configuration of the present invention, aspreviously disclosed. Radio Activity Controller 720 may be revised toinclude additional functionality for local control, yielding a combinedlocal controller 1112. This functionality may be included as additionalsoftware loaded into an existing radio activity controller 720, or as atotally new controller incorporating the functionality of both devices.As stated above, local controller 1112 serves to control the activity ofthe module to which it is coupled, while still acting within the boundsas set forth by the distributed multiradio control solution. Further,while the local controller is shown as being integrated within RadioActivity Controller 720, this controller may also be a separatecomponent coupled to radio modem 610 via common interface 620 or MCSinterface 710.

FIG. 11B uses example 1100 first presented in FIG. 11A in order tofurther describe how local controller 1102 may be integrated within thesystem of radio modem 610. Local control 1102 may be coupled to one orboth of common interface 620 and MCS interface 710 in order to receiveinformation from and send information to MRC 600. The informationreceived from MRC 600 may include schedule information for the radiomodem 610 which is being managed by local controller 1102. Informationsent from local controller 1102 to MRC 600 may include spectrum usageinformation, such as an indication of when the modem is actuallytransmitting or receiving information, information regarding messagesqueued for transmission, information regarding whether the messagewaiting to be sent has already been deferred, information about thecurrent state of a back-off timer, etc. Local control 1102 may furtherreceive information from the media access control layer (MAC) 1150 inand the physical layer (PHY) 1160 in radio modem 610. The MAC is thelayer that may control access for messages sent to the PHY layer, whichincludes at least the hardware resources utilized to send these messagesvia wireless communication in radio modem 610. These layers may alsoprovide information to local controller 1102, such as statistics aboutmessages queued for transmission, and carrier sensing including both theactual sensing of wireless traffic through clear channel assessment(CCA), or by virtual carrier sensing by monitoring message parameterssuch as a network allocation variable (NAV). CCA may include informationpertaining to the condition of a channel commonly utilized by radiomodem 610 for the wireless transmission of information. This informationmay be obtained, for example, through a process wherein radio modem 610uses resources in PHY layer 1160 to measure the energy signals on aparticular channel. If the energy signals are deemed to be above acertain level, then the channel is considered to be in use, and istherefore not available for use by radio modem 610. NAV, on the otherhand, is an indicator, maintained by each radio modem 610, of timeperiods when transmission onto the wireless medium will not be initiatedby radio modem 610, regardless of whether radio modem senses the carrieris busy through CCA, and may further take into account the durationfield in any received frame header. For example, if the start of a WLANframe is received, the carrier will be busy for at least the duration ofthe complete transaction (including the message frame andacknowledgement). When the NAV value is greater than 0, the “channelbusy” time can be known beforehand and may be used, in addition to CCA,to indicate the current channel state.

In an exemplary interaction between the above-identified entities in,local controller 1102 may receive schedule information from MRC 600,message queue and NAV information from MAC layer 1150, and CCAinformation from PHY layer 1160. The schedule information may beprocessed in order to yield a cut off indication. The cut off indicationmay, for example, be “true” or “high” during periods when no time hasbeen allocated for radio modem 610 to operate. This may occur when timehas been allocated to another radio modem 610 utilizing a possiblyconflicting wireless communication medium. CCA signal may likewise be“true” or “high” when the communication channel is busy, for example,when another device (outside of WCD 100) is using the channel. These twosignals may be combined in a logical “OR” and fed to MAC layer 1150. Asa result, when either of these two signals are “true” or “high” theresulting signal will be high, indicating to MAC layer 1150 that accessto the physical layer should be restricted. When these two prohibitiveconditions pass, then MAC layer may again allow messages to proceed tothe physical layer for immediate wireless transmission. While thissystem may account for schedule and channel availability, there is stillno accounting for whether a message to be sent from modem 610 can befully completed in the allowed time.

Referring now to FIG. 12A, a problematic scenario which at least oneembodiment of the present invention seeks to correct is now analyzed.The operation of an unscheduled wireless communication medium is mappedout in FIG. 12A. An operational schedule defined by MRC 600 is showncompared to what is actually occurring in the communication medium. Thegrey areas in the MRC schedule signify a period when radio modem 610 ispermitted to operate. Time not allocated to radio modem 610 may bereserved for other wireless resources in WCD 100. The WLAN schedulebelow the MRC schedule show an exemplary wireless transaction that mayoccur during this time period. Normal traffic can begin after the mediumhas been idle for at least DIFS (distributed coordination functioninter-frame space). Then during the contention window stationsattempting to transmit select a random back-off counter value, anddecrement the counter by one after each back-off slot where thecommunication channel is determined to be idle, signifying that notraffic has been detected on the channel. Once the counter reaches zeroand the medium is still idle, the transmit frame can begin. The DIFSperiod and contention window are the periods of time when carriersensing is occurring. When the transmission of the frame has beencompleted (as is in the case of Frame 1 shown in FIG. 12A) anacknowledgement frame may then be returned from the device that receivedthe original frame 1, and the transaction may be deemed complete inradio modem 610.

However, a problem is seen with respect to the transmission of frame 2.In this example, an extended period of contention and possibly moreinformation contained in the frame has pushed the completion of thisframe outside of the allowed air access time. This may be seen, forexample, where the NAV for the next queued message includes durationinformation showing that the transaction will exceed the time allocatedto radio modem 610. As a result, the entire frame 2 will not betransmitted to the receiving device, and further, no acknowledgementwill be received. This situation may require the retransmission of theframe, which may again fail if the situation in the next availabletransmission period resembles the scenario for exemplary frame 2. Theresources for one or more radio modems 610 may then become depleted dueto these retransmissions, possibly impairing the overall communicationperformance in WCD 100.

FIG. 12B now discloses a solution to the problem discussed above withrespect to frame 2 in accordance with at least one embodiment of thepresent invention. In FIG. 12B local controller 1102 is receivinginformation about messages queued for transmission via radio modem 610,for example, from MAC layer 1150. This information may include at leastthe size of the messages so that local controller may determine apredicted amount of time for transmission in view of current radio modemperformance, or alternatively, a predicted amount of time of fortransmission may be provided directly from MAC layer 1150. For example,if the NAV shows that a channel is busy longer than WLAN has air access,radio modem 610 may inform MRC 600 that it cannot transmit within theallowed time. Using this information, an algorithm for determiningwhether a transaction should proceed may be formulated using the MRCschedule, carrier sensing via CCA and/or NAV, and predicted messagecompletion time.

In the example presented with respect to frame 2 in FIG. 12B, initiallyit is determined through carrier sensing that due to the extendedcontention period there is not enough time remaining in the transmissionwindow to complete the transaction. Again, depending on thecommunication configuration in radio modem 610 and/or generally in WCD100, completing a successful transmission may require both thesuccessful sending of the complete frame and the receipt of theAcknowledgement frame. No benefit is realized if the entire frame 2 issent but no acknowledgement frame is received since the system will beforced to consider the message as failed and resend the message. In thenext WLAN air access period allocated to radio modem 610, the combinedDIFS and contention window is short, providing enough time for theentire transaction, as predicted, to complete. In this manner, thefrequency of failed communication transactions (and retransmissions) foran unscheduled wireless communication medium may be reduced, and theoverall communication efficiency in WCD 100 may be improved.

Now that an exemplary system has been set forth in accordance with atleast one embodiment of the present invention, specific examples ofoperation may be further explained. In a first operating scenario, aWLAN radio modem 610 may be initiating transmission (i.e. the contentionperiod has ended). The schedule information provided by MRC 600indicates that transmission rights will be cut off before the packettransmission is completed. WLAN radio module 610 may then defer thepacket transmission to a later time when an adequate period isavailable, and as a result, saves power and reduces spectrum clutter(see, for example, FIG. 12B). In another scenario, radio modem 610 maypreemptively defer transmission before the contention period has ended.For example, if during the contention period radio modem 610 sets NAV(e.g., receives a packet not addressed to itself) and the NAV+estimatedpacket transmission time is greater than the allocated schedule time,the frame cannot be transmitted successfully. Also, if NAV alone isgreater than the available air access time, WLAN cannot even decreasecontention counter before the air access window ends. The time remainingin the schedule for radio modem 610 may then be reported to MRC 600,which may reallocate this time to other modems, or alternatively, ifcommunication within WCD 100 is fast, MRC 600 may be able to allocateadditional time to radio modem 610 in order to allow the transaction tocomplete.

X. Back-off Timing.

FIG. 13A discloses an exemplary back-off timing diagram in accordancewith at least one embodiment of the present invention. A back-offcountdown may occur after DIFS in order to provide a random offset whichmay in turn prevent the simultaneous start of communication for multiplewireless transmitting devices on the same channel. A back-off countervalue may be chosen at random, which then decremented for each time slotwherein carrier sensing determines that the carrier is still available.In accordance with the present invention, the operation of the back-offcounter may be enhanced by accounted for time periods where it is knownthat the carrier will not be available, such as time indicated asoccupied by the MRC schedule along with time periods where the carrieris sensed to be unavailable.

As disclosed in the exemplary timeline of FIG. 13A, informationregarding whether a channel is available from a scheduling and carriersensing standpoint may be used to control the behavior of the back-offcounter. Initially, a random value is chosen for the back-off counter(in this example “N”). When the counter starts, N is decremented foreach time slot the carrier sensing detects that the transmission channelis free. However, an instance occurs in this example where the carriersensing shows the line to be busy while the MRC schedule still has timeallocated to the radio modem 610 (time t=N−a). The counter may then bepaused until the carrier becomes available. After DIFS, the counter maystart again from the same point, wherein t=N−a. The timer may continueto count down until the next pause instant where the MRC schedule nolonger permits transmission. This may occur, for example, due to theavailable transmission time being reserved for another radio modem 610in WCD 100. At this instant, t=N−b, the countdown time is again pauseduntil both the MRC schedule and carrier sensing again permittransmission. When both criteria are met DIFS may again occur, and thenthe timer may proceed counting down again from t=N−b until t=0 whenradio modem 610 sends the frame.

In another example of operation, WLAN radio modem 610 may initiate thetransmission procedure (i.e., carrier sensing including DIFS and thecontention window period), only to be interrupted by MRC 600 cutting offtransmission rights during the contention period but continuing to allowreception. This is a scenario depicted in FIG. 13B, wherein the MRCschedule is further defined to include a receiving schedule (RX) and atransmission schedule (TX). Contention may continue (including theback-off counter countdown) normally if at least reception is allowed.If the back-off counter reaches zero after the transmission rights havebeen restored, normal packet transmission may proceed (e.g., the firstscenario discussed above may operate here). However, a problem may occurwhen the back-off timer reaches zero without TX permission beingrestored. If the back-off counter reaches zero during the transmissioncut-off period (depicted in the area highlighted in the dashed oval inFIG. 13B), the transmission may be delayed until rights are restored toradio modem 610. Transmission may then begin immediately if the channelis still idle (e.g., the first scenario). This behavior may increase thethroughput of radio modem 610 and improve the overall efficiency of WCD100.

When a radio modem 610 utilizing an unscheduled wireless communicationmedium begins the transmission procedure (e.g., carrier sensingincluding DIFS and a contention window period), it is foreseeable thatMRC 600 may cut off both transmission and reception permission. Duringany reception cut-off period, the radio modem may assume (e.g., becauseCCA and Cut-Off indication from local controller 1102 are OR-ed as shownin FIG. 11B) that spectrum interference exists, causing local controller1102 to pause the back-off counter. This idle time may be spent inpower-saving mode (e.g., a sleep mode). If both rights are restored atthe same time, normal operation may then continue. If reception rightsare restored before transmission rights, radio modem 610 may continueaccording to the similar scenario described above. Alternatively, iftransmission rights are restored before reception rights, radio modem610 waits for reception rights to be restored. This time can be spent ina power-saving mode.

Referring to FIG. 14, a process flow in accordance with at least oneembodiment of the present invention is now described. The process beginsin step 1400 wherein there is an indication of information (e.g., atleast one message) to be transmitted via radio modem 610. Localcontroller 1102 may then initialize information gathering by obtaininginformation related to at least MRC operational scheduling, carriersensing and messages pending for transmission (step 1402). The messageinformation may include, for example, the number of messages pendingand/or the length or estimated transmission time for each message. Radiomodem 610 may then begin a process of determining whether messagetransmission is possible. Initially, the MRC schedule may be checked(step 1404). This check may include a determination as to whether radiomodem 610 is allowed to communicate (currently within an allocated timeperiod), and if permitted to communicate, whether or not messagetransmission may be completed (e.g., both message and acknowledgement)in the time allocated. If no time is currently reserved for radio modem610, or the message may not be completed in the remaining allocatedtime, then transmission may not proceed. As a result, the pendingmessage may be delayed, the back-off counter may be paused, statusinformation for radio modem 610 may be transmitted to MRC 600, andfurther, radio modem 610 may enter a power-saving mode until the channelis free.

If adequate time has been allocated for radio modem 610 in the MRCschedule, then in step 1408 the carrier status is checked to determineif any sensed communication is occurring on the channel. If, forexample, a power level exceeding a predetermined power level is sensed(e.g., indicating that the channel is busy), then delay and notificationactions as previously described with respect to step 1406 may continueuntil carrier sensing determines the channel to be free. After thecarrier sensing determines that the carrier is available, the back-offcounter may also be checked in step 1410 to determine if any timeremains before the back-off counter reaches zero. If time remains, thenin step 1412 the counter continues to run and MRC 600 may be informed ofthe radio modem 610 status. For each count, the MRC schedule and carriersensing status may again be checked (e.g., steps 1404 and 1406).Otherwise, if the back-off counter has reached zero, the MRC schedulemay again be checked in step 1414 to determine both if transmission ispermitted and if the transaction can be completed in the time remaining.Checking the MRC schedule again is important, for example, because asthe initial value for the back-off counter is random and the counter isput on hold when the channel is busy, there is no way to define the timeneeded for carrier sensing until the carrier sensing is completed. Ifthe time remaining is not sufficient, a delay may be required per step1406. If enough time remains so that the message transaction may becompleted, the message frame may be sent in step 1416.

FIG. 15 discloses another exemplary process flow in accordance with atleast one embodiment of the present invention. The process of FIG. 15describes an example of controlling a back-off counter in view ofoperational schedule information and carrier status. In step 1500, arandom back-off value may be set. This random value may be used as astarting point from which to count down to zero. An operational schedulemay be provided by MRC 600 in step 1502, which may be utilized in step1504 to determine if radio module 610 is allowed to communicate. If theoperational schedule does not allow communication, or it is determinedthat a channel is not available, for example, through carrier sensing(step 1506), then the back off-counter may be paused in step 1510.Otherwise, if communication is allowed by the operational schedule andthe carrier is determined to be available, then normal radio module 610operation in accordance with what has been set forth previously in thisdisclosure may continue in step 1508.

Finer operational schedule control may be available in some embodimentsof the present invention. FIG. 16 discloses a process flow wherein arandom back-off value may be set (step 1600) and an operational schedulereceived (step 1602) as in the previous example process. However, theoperational schedule in FIG. 16 may include separate periods definingseparately when radio module 610 may receive and transmit. For example,if radio module 610 is not allowed to receive incoming messages (step1604), then in step 1606 radio module 610 may be placed in apower-saving mode until reception is allowed. When reception is allowedper the operational schedule, transmission permission may then bedetermined in step 1608. If the operational schedule permitstransmission, then normal operation in radio module 610 may proceed instep 1610 in accordance with what has been set forth previously in thisdisclosure.

If transmission is not allowed by the operational schedule, then in step1612 the current value of the back-off timer may be checked. If thetimer has not counted down to zero, then carrier sensing in step 1614may determine the availability of the channel. If the channel isavailable, the back-off timer may be decremented in step 1616 and theprocess may begin again from step 1602. If the channel is not determinedto be available, then the back-off counter may be paused in step 1618.Alternatively, if it is determined that the back-off timer has counteddown to zero, then in step 1620 the initiation of the messagetransaction may be delayed while carrier sensing is continued. Theprocess flow may then return to step 1602 in order to recheck thecurrent status of at least the operational schedule and the channelavailability.

Accordingly, it will be apparent to persons skilled in the relevant artthat various changes in form a and detail can be made therein withoutdeparting from the spirit and scope of the invention. This the breadthand scope of the present invention should not be limited by any of theabove-described exemplary embodiments, but should be defined only inaccordance with the following claims and their equivalents.

1. A method, comprising: receiving scheduling information indicating atleast one allowed time period within which a radio module is allowed tocommunicate; receiving information related to at least one message to besent via the radio module; determining the availability of acommunication channel; if the radio module is allowed to communicate,determining whether the time remaining in the allowed time period issufficient for completing a transaction including the at least onemessage; and if the time remaining in the allowed time period issufficient for completing the transaction, initiating the transactionincluding the at least one message.
 2. The method of claim 1, whereinthe scheduling information is provided by a multiradio controllerincorporated in the same wireless communication device as the radiomodule.
 3. The method of claim 1, wherein receiving information relatedto at least one message to be sent via the radio module includesreceiving one or more messages for transmission via the WLANcommunication medium and information regarding the length or predictedtransmission time of each message.
 4. The method of claim 1, whereindetermining the availability of a communication channel includes carriersensing via at least one of actual carrier sensing using clear channelassessment (CCA) or virtual carrier sensing using a network allocationvector (NAV).
 5. The method of claim 1, wherein, if an immediateacknowledgement is required, the complete message transaction includessending the message and receiving an acknowledgement.
 6. The method ofclaim 1, wherein if the radio module is not allowed to communicate orthe communication channel is not available, delaying the transactionuntil a later time period and notifying a multiradio controller of anytime remaining in the allowed time period.
 7. The method of claim 6,wherein delaying the transaction until a later time period furtherincludes pausing a back-off counter until the radio module is allowed tocommunicate and carrier sensing shows that the communication channel isavailable.
 8. The method of claim 7, wherein the transaction isinitiated if the radio module is allowed to communicate, thecommunication channel is available and the back-off counter has finishedcounting down.
 9. A computer program product comprising a computerusable medium having computer readable program code embodied in saidmedium, comprising: a computer readable program code for receivingscheduling information indicating at least one allowed time periodwithin which a radio module is allowed to communicate; a computerreadable program code for receiving information related to at least onemessage to be sent via the radio module; a computer readable programcode for determining the availability of a communication channel; acomputer readable program code for, if the radio module is allowed tocommunicate, determining whether the time remaining in the allowed timeperiod is sufficient for completing a transaction including the at leastone message; and a computer readable program code for, if the timeremaining in the allowed time period is sufficient for completing thetransaction, initiating the transaction including the at least onemessage.
 10. The computer program product of claim 9, wherein thescheduling information is provided by a multiradio controllerincorporated in the same wireless communication device as the radiomodule.
 11. The computer program product of claim 9, wherein receivinginformation related to at least one message to be sent via the radiomodule includes receiving one or more messages for transmission via theWLAN communication medium and information regarding the length orpredicted transmission time of each message.
 12. The computer programproduct of claim 9, wherein determining the availability of acommunication channel includes carrier sensing via at least one ofactual carrier sensing using clear channel assessment (CCA) or virtualcarrier sensing using a network allocation vector (NAV).
 13. Thecomputer program product of claim 9, wherein, if an immediateacknowledgement is required, the complete message transaction includessending the message and receiving an acknowledgement.
 14. The computerprogram product of claim 9, wherein if the radio module is not allowedto communicate or the communication channel is not available, delayingthe transaction until a later time period and notifying a multiradiocontroller of any time remaining in the allowed time period.
 15. Thecomputer program product of claim 14, wherein delaying the transactionuntil a later time period further includes pausing a back-off counteruntil the radio module is allowed to communicate and carrier sensingshows that the communication channel is available.
 16. The computerprogram product of claim 15, wherein the transaction is initiated if theradio module is allowed to communicate, the communication channel isavailable and the back-off counter has finished counting down.
 17. Asystem comprising: a wireless communication device, the wirelesscommunication device including at least: a multiradio controller; and aplurality of radio modules coupled to the multiradio controller, atleast one of the plurality of radio modules including a local controllerfor managing an unscheduled wireless communication medium; the localcontroller receiving scheduling information from the multiradiocontroller indicating at least one allowed time period within which aradio module is allowed to communicate; the local controller receivinginformation related to at least one message to be sent via the radiomodule and further determining the availability of a communicationchannel; if the radio module is allowed to communicate, the localcontroller further determining whether the time remaining in the allowedtime period is sufficient for completing a transaction including the atleast one message; and if the time remaining in the allowed time periodis sufficient for completing the transaction, the local controllerinitiating the transaction including the at least one message.
 18. Anapparatus, comprising: means for receiving scheduling informationindicating at least one allowed time period within which a radio moduleis allowed to communicate; means for receiving information related to atleast one message to be sent via the radio module; means for verifyingwhether the time remaining in the allowed time period is sufficient forcompleting a transaction including the at least one message; means for,if the time remaining in the allowed time period is sufficient forcompleting the transaction including the at least one message,determining the availability of a communication channel; and means for,if the radio module is allowed to communicate and the communicationchannel is available, initiating the transaction including the at leastone message.